ansc 255 exam 2

during and after slaughter the body is trying to maintain ----

homeostasis

exsanguination makes blood pressure -----, hear pump ----, and results in complete loss of --- system

decrease, faster, circulatory

when the circulatory system is lost, it means

nothing goes to or from muscle

after slaughter, there is a shift from aerobic to ---- metabolism

anerobic

what is rigor mortis in terms of actin/myosin crossbridges

actin cant let go of the myosin without the ATP, so it gets stuck

why does the shift from aerobic to anerobic metabolism after slaughter result in pH decrease

because of the accumulation of lactic acid

pre rigor chilling is when you chill the body before it hits rigor, which results in -----

short sarcomeres= tough meat

Pale, soft, exudative (PSE) is generally due to ----- stress

acute stress

PSE prior to slaughter: -----heart rate and temp, ATP is ------, there is a switch to anaerobic metabolism which leads to ------

decrease, depleted, build up in lactic acid

PSE after slaughter: ------ muscle temp, continuous build up of lactic acid, ------ pH decrease, ----- muscle to meat

increased, rapid, accelorated

results of PSE:

-increased temp and decreased pH=

-decreased ability to bind water=

-increased purge=

=loss of structural integrity=

-denatured proteins

-exudative (purge)

-pale

-soft

PSE quality problems:

Visual, juciness, tenderness, processing

Vis; looks pale

Juiciness; super dry

tenderness; little change, linked to juciness

processing; doesn't hold ingredients

Dark cutters before slaughter: ----- pH decrease, ------- glycogen

rapid, depleted

DC post harvest: ------ lactic acid production, less protein denaturation = ----- water binding

decrease, increase

DC results:

-increased water binding= increase in myoglobin = ------

-less denaturation= ------

-increase water binding = decrease purge = ------

dark color, firm texture, dry appearance

if beef is marked a dark cutter, can it be graded by the USDA?

no

DC quality problems:

visual, juiciness, tenderness, flavor, processing

vis: dark

juiciness: very juicy

flavor: off flavor

processing: holds water well, but has more Aw for bacteria

What are the 3 causes of bruising and broken bones?

-over filling transportation

-poor handling

-poor plant design

what is the most common problem with facilities? what do we want the animals to do?

-distractions

-want them to move on their own

what is the most important aspect of meat at purchase?

color

what can 4 things cause differences in meat color

-species

-sex

-muscle location

-age

Myoglobin's main function is -----, and it is the main source of ---- in meat. binding to the --- ligand determines meat color

-O2 transport

-Fe

-6th

Mb/DeOxyMb has ---- bound at 6th ligand and is the color -----

nothing; purple

OxyMb has ---- bound at 6th ligand and is the color -----

O2; red

MetMb has ---- bound at 6th ligand and is the color -----

H2O; brown

What 4 things cause Mb oxidation

oxygen, light, heat, ingredients

What 4 things effect palatability

tenderness, juiciness, flavor, appearance

What are the 3 MAJOR things that effect tenderness

-connective tissue

-sarcomere length

-proteolytic enzymes (aging post mortem)

Tenderness- connective tissue causes -------. it is made from ------, which the amount and chemical crosslinking determine how tough it is

background toughness, collagen

Tenderness- sarcomere link means that ---- length = ----- tenderness

increased, increased

proteolytic enzymes ----enzymes post mortem

degrades

What are the 2 Ca dependent calpains? what is the 1 calpain inhibitor?

m-calpain, u-calpain, calpastatin

How does marbling effect tenderness

it doesn't really effect it that much

juiciness is very related to ----

tenderness

What are the 2 things that most effect juiciness

Intramuscular fats, water

Flavor is a mix of -----+------

gustatory (taste) = olfactory (smell)

species flavor from ----

fat

what are the 3 additional things that effect flavor

sex, post mortem aging, lipid oxidation/racidity

High cookery:

-temps

-methods

-cuts used:

temps: high= >250

methods: high= broil, grill, fry

cuts used: high= steaks, chops, chicken

Low cookery:

-temps

-methods

-cuts used:

temps: 190-240

methods: braise, simmer, smoke

cuts used: roasts, ribs, stews

High

- speed/wetness

-tenderness

-flavor

-juiciness

- speed/wetness: fast and dry

-tenderness: toughens

-flavor: gains flavor naturally

-juiciness: dryer

Low cookery:

- speed/wetness

-tenderness

-flavor

-juiciness

-speed/wetness: slow and moist

-tenderness: tender

-flavor: must add flavor

-juiciness: dryer

what are 4 reasons to process meat

-preservation

-flavor/palatability

-convenience

-add value

what are the important ingredients to processed meat?

water and salt

what are the optional (but advised) ingredients

seasonings, phosphates, and nitrites

what does adding water as an ingredient do?

-disperses other ingredients

-temp control

-increases juiciness when it has help

what does adding salt as an ingredient do?

-extracts proteins (myofibrillar

-adds flavor

-helps with WHC

what does adding phosphates as an ingredient do?

-increases pH

-improves WHC

Salt moves the -----, while phosphate ------

iso electric point, moves pH

what does adding seasoning as an ingredient do?

-provides product identity

what does adding nitrite as an ingredient do?

-increase shelf life

-sets cured pink color (must add heat)

Fresh is ---cooked, ------smoked, ----- cured

uncooked, not smoked, uncured

Smoked, uncooked has no -------, ----- cured, and has a ----- smoke

thermal process, uncured, cold

Fully cooked ----- RTE, ------- smoked, ------cured, ------shelf stable

is, may or may not be smoked, usually cured, not

luncheon loaves ------ cooked, ----- RTE

fully cooked, are RTE

Dry/ Semi dry has ---- pH, ------ shelf stable

lowers, may or may not be

fermented dry/semi dry means

bacteria convert carbs to lactic acid

acidified dry/semi dry means

encapsulated acid (cheaper)

Nitrite (NO2-) prevents --------- flavor, inhibits -------

warmed over flavor, micro growth

sodium erthorbate/ascorbate

helps nitrite speed up the curing process

Nitroso metMb is the color ----- and has ----- bound to 6th ligand

brown, NO

Nitroso Mb is the color ------

dark red

when heat is added to Nitroso Mb it becomes --------, which is the color -----

Nitrosochemochrome, pink

what is an alternative to adding NO2-

celery juice

methods of curing whole muscles: Dry rub

-no water added

-slow (1 inch per week)

-Pro: increase in quality

-Con: slow and bone sour

methods of curing whole muscles: Pickle/brine

-uses water

-immerse or soak (slow)

-pump/inject (fast)

-Pro: fast

-Con: decreased quality if too fast, possiblemicrobial growth

Holstein cow is known for:

high volume of milk

Jersey cow has the ---- body size, is the most ------- tolerant breed, and its milk has -------

smallest, heat, high butterfat

Brown Swiss are considered the ----- breed, and its milk has -----, which is good for -------

oldest, high protein : fat ratio, cheese

Guernsey cow is ------ color, and its milk has ---------. The milk is the color -----

blonde red, high beta carotene (vitamin A), yellow color

Ayrshire cow is known for -----

easily adapting to its environment

milking shorthorn is a ----- breed, and has a -------- ratio

duel purpose, protein:fat

------- is another word for udder

mammory gland

inguinal canal

pathway from the body into the udders

why is a strong suspensory needed for the udder?

because it is heavy

how much can an udder weigh before milking?

110 lbs

--- teat(s) per portion of the udder

1

aveoli and small ducts

-secrete milk

-take nutrients from the body to make milk

large/major ducts

-DONT make milk

-basically just transportation for milk

gland cistern

-continuous with teat cistern

-contains 15-20 major ducts

annular fold

-dense pieced of connective tissue before entering the teat

teat cistern

-holds .5-1.5 oz of milk

teat meatus/streak canal

-3-5 convex epithelial projections

- prevents the escape of milk

- barrier to bacteria and foreign material

Is colostrum for human consumption?

no

what is a fresh cow?

cow 20 days post partum

what is a early lactation cow?

-20-150d

when is a dairy cow bred? when is her peak lactation?

90d, 40d

What are the 5 steps of millking

1. disinfect udder

2. strip the udder

3. wipe disinfectant off udder

4. place machine on udder

5. disinfect udder

Milk composition:

water-

carbs-

fat-

protein-

vitamins/minerals-

87%

5%

3%

3%

1%

difference between alpha and beta lactose

alpha:

-high temp = more soluble; low temp= crystalize

beta:

-low temp= soluble; high temp= crystalize

when does lactose crystalize?

when the concentrations of lactose exceed its solubility

Fat in milk:

----%saturated FA

----%monounsaturated FA

----%polyunsaturated FA

-65

-30

-5

Casien family protein is ------% of protein, ---- contain phosphorus, and precipitates at pH of ----

-82

-does

-4.6

Casien family protein is random in structure because ----. Is casien protein stable to heat treatment?

-allows to bind to Ca

-yes

Serum (whey) protein is ----% of protein, ----- Phosphorus, and ------ at pH 4.6

-18

-no

-stays in solution

serum (whey) protein contains large amounts of -------, and is ------- heat sensitive. this causes denaturation which = ---- water binding

-sulfur containing AA

-very

-increased

name 3 water soluble vitamins

- thiamin (B1)

-Riboflavin (B2

-Niacin (B3)

name 4 fat soluble vitamins

A, D, E, K

milk fortification with vitamin A is -------; fortification with vitamin D is ------

-required

-voluntary

milk is a good source of what mineral?

Calcium